Layout constraint manipulation via user gesture recognition

ABSTRACT

Systems and methods are described herein for enabling a user of a diagramming system to select elements of a diagram and apply a layout constraint thereto. In accordance with certain embodiments described herein, the systems and methods provide the user with a means to perform these tasks in a manner that is faster, easier and more intuitive than interfaces provided by conventional diagramming systems. For example, in accordance with at least one embodiment described herein, a single user gesture is obtained and the steps of selecting elements of a diagram to which a layout constraint is to be applied and selecting the layout constraint are both performed based on the single user gesture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/687,388, now allowed, filed on Jan. 14, 2010,and entitled “Layout Constraint Manipulation via User GestureRecognition,” the entirety of which is incorporated by reference herein.

BACKGROUND

Computer-implemented diagramming systems exist that enable users toauthor and edit graphical diagrams. To facilitate the authoring ofcomplex diagrams, such as complex network diagrams or graphs, certaindiagramming systems include a feature termed automatic layout. Inaccordance with this feature, the diagramming system automaticallygenerates a diagram based on data that specifies the elements to beincluded in the diagram and any relationships there between, as well ason a set of rules or algorithms that govern certain layoutconsiderations such as the size and placement of diagram elements.

Some diagramming systems that support automatic layout also supportuser-defined layout constraints. A layout constraint specifies apersistent layout relationship between certain elements in a diagram.Layout constraints provide a means by which a user can tailor or finetune a diagram without having to explicitly position diagram elements.When a user defines a layout constraint with respect to diagramelements, the diagramming system sets up a persistent layoutrelationship between the diagram elements that is maintained insubsequent interactions. The layout constraint is maintained until suchtime as the user explicitly removes it. Examples of layout constraintsinclude but are not limited to constraints that control the alignment ofdiagram elements, the distribution of diagram elements, and theseparation between diagram elements.

User interfaces associated with certain conventional diagramming systemsthat support user-defined layout constraints are limited in that, toapply a layout constraint, the user must first select the elements thatare to be involved in the constraint, and then must separately choosewhich type of constraint to apply.

SUMMARY

Systems and methods are described herein for enabling a user of adiagramming system to select elements of a diagram and apply a layoutconstraint thereto. In accordance with certain embodiments describedherein, the systems and methods provide the user with a means to performthese tasks in a manner that is faster, easier and more intuitive thaninterfaces provided by conventional diagramming systems. For example, inaccordance with at least one embodiment to be described herein, a singleuser gesture is obtained and the steps of selecting elements of adiagram to which a layout constraint is to be applied and selecting thelayout constraint are both performed based on the single user gesture.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Moreover, itis noted that the invention is not limited to the specific embodimentsdescribed in the Detailed Description and/or other sections of thisdocument. Such embodiments are presented herein for illustrativepurposes only. Additional embodiments will be apparent to personsskilled in the relevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate embodiments of the present inventionand, together with the description, further serve to explain theprinciples of the invention and to enable a person skilled in therelevant art(s) to make and use the invention.

FIG. 1 is a block diagram of an example diagramming system thatfacilitates the manipulation of user-defined layout constraints via usergesture recognition.

FIG. 2 is a block diagram that shows components of a diagramming modulein accordance with one example embodiment.

FIG. 3 is a flowchart that depicts a method for manipulatinguser-defined layout constraints via user gesture recognition inaccordance with an example embodiment.

FIG. 4 is a flowchart that depicts one method for identifying a usergesture based on input received via one or more user input devices.

FIG. 5 depicts a portion of an exemplary diagram rendered to a displaydevice.

FIG. 6 depicts a portion of the exemplary diagram of FIG. 5 to which apath defined by a user gesture has been mapped, wherein the pathintersects elements of the diagram.

FIG. 7 depicts a portion of the exemplary diagram of FIGS. 5 and 6 aftera horizontal alignment constraint has been applied to the intersectedelements.

FIG. 8 is a flowchart that depicts a method for selecting a layoutconstraint to be applied to elements of a diagram based on the manner inwhich a path defined by a user gesture intersects one or more elementsof the diagram.

FIG. 9 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the manner in which the path intersects elements of the diagramindicates a diagonal alignment constraint is to be applied to theintersected elements.

FIG. 10 depicts a portion of the exemplary diagram of FIG. 9 after adiagonal alignment constraint has been applied to the intersectedelements.

FIG. 11 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the manner in which the path intersects elements of the diagramindicates a horizontal alignment constraint is to be applied to theintersected elements.

FIG. 12 depicts a portion of the exemplary diagram of FIG. 11 after ahorizontal alignment constraint has been applied to the intersectedelements.

FIG. 13 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the manner in which the path intersects elements of the diagramindicates a vertical alignment constraint is to be applied to theintersected elements.

FIG. 14 depicts a portion of the exemplary diagram of FIG. 13 after avertical alignment constraint has been applied to the intersectedelements.

FIG. 15 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the manner in which the path intersects elements of the diagramindicates a circular alignment constraint is to be applied to theintersected elements.

FIG. 16 depicts a portion of the exemplary diagram of FIG. 15 after acircular alignment constraint has been applied to the intersectedelements.

FIG. 17 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the path forms a shape that encloses various elements of thediagram.

FIG. 18 depicts a portion of the exemplary diagram of FIG. 17 after agrouping constraint has been applied to the enclosed elements.

FIG. 19 depicts a portion of an exemplary diagram rendered to a displaydevice to which a path defined by a user gesture has been mapped,wherein the manner in which the path intersects elements of the diagramindicates a horizontal alignment constraint is to be applied to theintersected elements

FIG. 20 depicts a portion of the exemplary diagram of FIG. 19 after ahorizontal alignment constraint has been applied to the intersectedelements, the horizontal alignment constraint being implemented byaligning ports of the intersected elements.

FIG. 21 is a flowchart that depicts a method for using user gestures toassociate a layout constraint involving a first set of diagram elementswith a second set of diagram elements.

FIG. 22 depicts an example computer system that may be used to implementvarious aspects of the embodiments.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. The drawing in which an elementfirst appears is indicated by the leftmost digit(s) in the correspondingreference number.

DETAILED DESCRIPTION I. Introduction

The following detailed description refers to the accompanying drawingsthat illustrate exemplary embodiments of the present invention. However,the scope of the present invention is not limited to these embodiments,but is instead defined by the appended claims. Thus, embodiments beyondthose shown in the accompanying drawings, such as modified versions ofthe illustrated embodiments, may nevertheless be encompassed by thepresent invention.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” or the like, indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Furthermore, whena particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the relevant art(s) to implement suchfeature, structure, or characteristic in connection with otherembodiments whether or not explicitly described.

II. Example Systems and Methods for Manipulating Layout Constraints ViaUser Gesture Recognition

FIG. 1 is a block diagram of an example diagramming system 100 thatfacilitates the manipulation of user-defined layout constraints via usergesture recognition. As shown in FIG. 1, diagramming system 100 includesa processor-based computing platform 102, a display device 104 that isconnected to computing platform 102, and one or more user input devices106 that are also connected to computing platform 102. Diagrammingsystem 100 is intended to broadly represent any processor-based systemupon which software may be executed for the benefit of a user. Forexample and without limitation, diagramming system 100 may comprise adesktop computing system, a laptop computer, a tablet computer, a videogaming system, a personal digital assistant (PDA), a smart phone, or aportable media player. A specific example of a processor-based computersystem that may be used to implement diagramming system 100 will bedescribed subsequently herein in reference to FIG. 22.

As further shown in FIG. 1, computing platform 102 includes at least aprocessing unit 112, a memory 114, a display device interface 116 andone or more user input device interfaces 118. These components areinterconnected via a communication infrastructure 120, which maycomprise for example one or more bus structures.

Processing unit 112 comprises one or more processors or processor coresthat are configured to execute software modules and to access datastored in memory 114. The software modules stored in memory 114 includeat least a diagramming module 122 and a user gesture processing module124. The data stored in memory 114 includes at least a predefinedgestures library 126. Memory 114 is intended to broadly represent anytype of volatile memory, non-volatile memory, or combination thereof,and may be implemented across one or more storage devices or systems.

Display device interface 116 comprises an interface that renders videoor graphics information received from processing unit 112 or memory 114for display on display device 104. Display device interface 116 maycomprise, for example, a video or graphics card that is configured toperform video or graphics rendering operations. Depending upon theimplementation of diagramming system 100, display device 104 maycomprise a monitor, a projector, or other type of display device that isphysically separate from computing platform 102 and connected theretovia a suitable wired and/or wireless connection, or a display devicethat is integrated within the same physical structure as computingplatform 102, such as an integrated display in a laptop computer, tabletcomputer, PDA or portable media player.

User input device interface(s) 118 comprise one or more interfaces forreceiving user input information generated by user input device(s) 106and for passing such input information to processing unit 112 forprocessing thereof. Depending upon the implementation, user inputdevice(s) 106 may include a mouse, a keyboard, a touch pad, a trackball,a joystick, a pointing stick, a touch screen (e.g., a touch screenintegrated with display device 104), a wired glove, a motion trackingsensor, a game controller or gamepad, or a video capture device such asa camera. However, these examples are not intended to be limiting anduser input device(s) 106 may include other types of devices other thanthose listed herein. Depending upon the implementation, each user inputdevice 106 may be physically separate from computing platform 102 andconnected thereto via a suitable wired and/or wireless connection, ormay be integrated within the same physical structure as computingplatform 102, such as an integrated keyboard, touchpad, or touch screenon a laptop computer, tablet computer, PDA or portable media player.

Diagramming module 122 is a software module that, when executed byprocessing unit 112, enables a user of diagramming system 100 to authorand edit graphical diagrams. During execution of diagramming module 122,diagram authoring and editing functions may be invoked by the user viamanipulation of one or more of user input device(s) 106. The user inputinformation generated through such manipulation is passed to processingunit 112 via user input device interface(s) 118. Processing unit 112processes such user input information so that it can be properlyinterpreted by executing diagramming module 122. Furthermore, duringexecution of diagramming module 122, diagrams authored or edited by auser are rendered to display device 104 via display device interface 116for viewing and/or manipulation by the user.

When executed by processing unit 112, diagramming module 122 alsoenables a user to invoke the automatic layout of diagrams and to applyuser-defined layout constraints to elements of such diagrams. Whenautomatic layout of diagrams is utilized, a diagram, such as a networkdiagram or graph, is automatically generated based on data thatspecifies elements to be included in the diagram and relationships therebetween, as well as on a set of rules or algorithms that govern certainlayout considerations such as the size and placement of diagramelements. The generated diagram, or at least a portion thereof, isrendered to display device 104 via display device interface 116 forviewing and/or manipulation. The generation of a diagram using automaticlayout may encompass both the generation of a new diagram and theupdating or modification of an existing diagram.

Layout constraints specify a persistent layout relationship betweencertain elements in a diagram. Layout constraints provide a means bywhich a user can tailor or fine tune a diagram without having toexplicitly position diagram elements. When a user defines a layoutconstraint with respect to diagram elements, a persistent layoutrelationship is created between the diagram elements that is maintainedin subsequent interactions. The layout constraint is maintained untilsuch time as the user explicitly removes the constraint. Examples oflayout constraints include but are not limited to constraints thatcontrol the alignment of diagram elements, the distribution of diagramelements, and the separation between diagram elements.

Various methods for performing automatic layout and implementing layoutconstraints in a diagramming system are described in the literature andthus need not be described herein. For example, certain techniques forimplementing these features are described in the references T. Dwyer, etal., “Dunnart: A Constraint-based Network Diagram Authoring Tool,” Proc.16^(th) Intl. Symp. Graph Drawing (GD'08), volume 5417 of Lecture Notesin Computer Science, pages 420-431 (Springer, 2009) and T. Dwyer,“Scalable, Versatile and Simple Constrained Graph Layout,” Proc.Eurographics/IEEE-VGTC Symp. on Visualization (Eurovis 2009). Each ofthese references is incorporated by reference herein.

As will be described in more detail herein, diagramming module 122 isconfigured to enable processing unit 112 to obtain a single user gestureand to process the user gesture to select one or more elements of adiagram to which a layout constraint is to be applied and also to selectthe layout constraint to be applied to the selected elements. Thus,diagramming module 122 advantageously provides the user with a means toperform these tasks in a manner that is faster, easier and moreintuitive than interfaces provided by conventional diagramming systems.

To facilitate obtaining a user gesture, processing unit 112 executesuser gesture processing module 124. User gesture processing module 124is configured to enable processing unit 112 to capture a user gesturebased on user input information received from user input device(s) 106via user input device interface(s) 118. The user gesture may be a singletouch user gesture or a multi-touch user gesture. User gestureprocessing module 124 is further configured to determine whether or notthe user gesture so captured matches any predefined user gestures storedin predefined user gestures library 126 and to pass recognized usergestures to an executing version of diagramming module 122.

FIG. 2 is a block diagram that depicts diagramming module 122 in moredetail in accordance with one example embodiment. As shown in FIG. 2,diagramming module 122 includes a plurality of modules including adiagram element selection module 202, a user gesture to constraintmapping module 204, a layout constraint application module 206 and adiagram rendering module 208. Diagram element selection module 202comprises logic that, when executed by processing unit 112, selects oneor more elements of a diagram based on a user gesture obtained viaexecution of user gesture processing module 124. User gesture toconstraint mapping module 204 comprises logic that, when executed byprocessing unit 112, selects a layout constraint based on a user gestureobtained via execution of user gesture processing module 124. Layoutconstraint application module 206 comprises logic that, when executed byprocessing unit 112, applies a layout constraint selected by usergesture to constraint mapping module 204 to one or more elementsselected by diagram element selection module 202. Diagram renderingmodule 208 comprises logic that, when executed by processing unit 112,renders a diagram or portion thereof to display device 104 via displaydevice interface 116.

In one implementation, diagramming module 122, user gesture processingmodule 124 and predefined user gestures library 126 all comprisecomponents of the same software application. For example, diagrammingmodule 122, user gesture processing module 124 and predefined usergestures library 126 may all comprise components of a diagrammingapplication or an application that includes built-in diagrammingcapabilities. In an alternate implementation, diagramming module 122 anduser gesture processing module 124 comprise separate applications. In afurther alternate implementation, diagramming module 122 comprises allor a portion of a diagramming application and user gesture processingmodule 124 and predefined user gestures library 126 comprise componentsof an operating system upon which diagramming module 122 is executed.Still other implementations are possible.

In an alternate implementation not shown in FIG. 1 or 2, thefunctionality of diagramming system 100 is implemented in aclient-server environment. In accordance with such an implementation,various functions performed by diagramming system 100 are distributedbetween a client computer and a server computer, wherein the clientcomputer and server computer are communicatively connected via one ormore networks. For example, in accordance with one such implementation,a client computer may be used to receive user input, obtain usergestures therefrom, and to display diagrams for viewing and/ormanipulation by a user, while a server computer may be used to performthe remaining diagramming-related functions of system 100. Otherapproaches to distributing functionality between a client computer and aserver computer may be utilized.

FIG. 3 depicts a flowchart 300 of a method for manipulating user-definedlayout constraints via user gesture recognition in accordance with anexample embodiment. Although the method of flowchart 300 will bedescribed herein in reference to various elements of diagramming system100 as described above in reference to FIGS. 1 and 2, persons skilled inthe relevant art(s) will readily appreciate that the method is notlimited to that implementation and may be implemented by other systemsor elements.

As shown in FIG. 3, the method of flowchart 300 begins at step 302 inwhich diagram rendering module 208 is executed by processing unit 112 torender at least a portion of a diagram to display device 104. Thediagram comprises a plurality of elements. For example, in an embodimentin which the diagram comprises a network diagram or graph, the elementsmay comprise nodes in the network diagram or graph. As another example,the elements may also comprise edges that connect such nodes. Stillother types of elements may be included within a diagram.

At step 304, user gesture processing module 124 is executed byprocessing unit 112 to identify a user gesture based on input receivedvia at least one of user input device(s) 106. At least one manner ofperforming this step will be described in more detail below.

At step 306, diagram element selection module 202 is executed byprocessing unit 112 to select one or more of the elements of the diagrambased on the user gesture identified during step 304.

At step 308, user gesture to constraint mapping module 204 is executedby processing unit 112 to select a layout constraint from among aplurality of layout constraints made available by diagramming module 122based on the user gesture identified during step 304.

At step 310, layout constraint application module 206 is executed byprocessing unit 112 to apply the layout constraint selected during step308 to the element(s) selected during step 306.

At step 312, diagram rendering module 208 is executed by processing unit112 to render at least a portion of the diagram to display device 104after application of the selected layout constraint to the selectedelement(s). During this step, if the application of the selected layoutconstraint to the selected element(s) has caused a change in the layoutof the diagram, that change may be made apparent to the user when thediagram, or portion thereof, is viewed by the user on display device104.

FIG. 4 is a flowchart 400 that depicts one method for identifying a usergesture based on input received via one or more user input devices. Themethod of flowchart 400 may be used, for example, to implement step 304of flowchart 300 which was described above in reference to FIG. 3.Although the method of flowchart 400 will be described herein inreference to various elements of diagramming system 100 as describedabove in reference to FIGS. 1 and 2, persons skilled in the relevantart(s) will readily appreciate that the method is not limited to thatimplementation and may be implemented by other systems or elements.

As shown in FIG. 4, the method of flowchart 400 begins at step 402, inwhich user gesture processing module 124 is executed by processing unit112 to capture a user gesture based on input received via at least oneof user input device(s) 106. As will be appreciated by persons skilledin the art, the manner in which a user gesture is captured will dependat least in part on the type of user input device(s) used to perform thegesture. For example, in one embodiment in which a mouse is used toperform the gesture, user gesture processing module 124 may causeprocessing unit 112 to initiate capture of a user gesture when a userdepresses a particular button on the mouse. While the button isdepressed, the movement of the mouse across a mouse pad or other surfaceis tracked to determine a path or shape associated with the usergesture. When the button is released, capture of the user gesture iscompleted.

In an embodiment in which a touch screen is used to capture the usergesture, the user gesture may be captured by tracking the touch of afinger or stylus against the touch screen during a designated captureperiod. A similar approach may be used for a touch pad. In alternateembodiments that utilize motion tracking sensors and/or video capturedevices such as cameras, the motions of a user in space may be trackedand interpreted to capture gestures. Still other techniques may be usedpremised on the use of any of the aforementioned types of user inputdevices or based on various other types of user input devices. Incertain implementations, more than one user input device may used tocapture the user gesture.

At step 404, the user gesture captured during step 402 is compared tothe predefined user gestures stored in predefined user gestures library126. At decision step 406, if a matching predefined user gesture isfound, then the user gesture captured during step 402 is deemedrecognized and the matching predefined user gesture is passed todiagramming module 122 as shown at step 408. However, if no matchingpredefined user gesture is found, then the user gesture is capturedduring step 402 is deemed unrecognized and control flows back to step402 to capture another user gesture.

The foregoing describes only one example of a method for identifying auser gesture based on input received via one or more user input devices.Persons skilled in the relevant art(s) will readily appreciate that anyof a wide variety user gesture recognition systems and algorithms may beused to perform this function. For example, in accordance with oneembodiment, a low-complexity user gesture recognizer may be used such asthat described in J. Wobbrock et al., “Gestures without Libraries,Toolkits or Training: A $1 Recognizer for User Interface Prototypes,”ACM Symposium on User Interface Software and Technology (UIST) '07, Oct.7-10, 2007, Newport, R.I. (2007). Still other types of user gesturerecognizers may be used.

In one embodiment, the step of selecting one or more elements of thediagram based on the identified user gesture as described above inreference to step 306 of flowchart 300 comprises selecting elements ofthe diagram that are intersected by a path defined by the user gesture.This will now be illustrated with respect to FIGS. 5-7, each of whichdepicts a portion of an exemplary diagram that has been rendered todisplay device 104 via the execution of diagram rendering module 208. Asshown in FIG. 5, the portion of the diagram includes a plurality ofnodes 502, 504, 506, 508, 510 and 512 and a plurality of edges 512, 514,516, 518, 520 and 522. Edge 512 connects node 502 to node 504, edge 514connects node 504 to node 506, edge 516 connects node 506 to node 508,and edge 518 connects node 506 to node 510. Edges 520 and 522 connectnode 512 to other nodes that are not shown within the display area ofdisplay device 104. In the portion of the diagram shown in FIG. 5, eachnode is intended to represent a table in a relational database and eachedge is intended to represent a relationship between two tables, such asfor example a shared field or column. However, this is only one example.Persons skilled in the relevant art(s) will appreciate that each nodemay represent a wide variety of entity types and that each edge mayrepresent a wide variety of relationship types depending upon theapplication. As shown in FIG. 5, a particular layout of nodes and edgeshas been generated via execution of diagram rendering module 208. Thislayout may have been automatically generated in accordance with one ormore automatic layout rules and one or more user-defined layoutconstraints.

FIG. 6 depicts the portion of the exemplary diagram rendered to displaydevice 104 after a user gesture has been captured and recognized viaexecution of user gesture processing module 124. After recognition ofthe user gesture, diagramming module 122 is executed to map a pathassociated with the user gesture to the portion of the diagram displayedby display device 104. This path is depicted as path 602 in FIG. 6. Inone embodiment, diagram rendering module 208 is executed to render aline along path 602, thereby providing a user with a visual indicationof the path of the user gesture and how it aligns with the displayedportion of the diagram.

As shown in FIG. 6, path 602 intersects nodes 502, 504, 506, 510 and512. In accordance with one embodiment, diagram element selection module202 is configured to select these nodes as the nodes to which a layoutconstraint will be applied by virtue of the fact that these nodes areintersected by path 602.

In addition to performing node selection based on path 602 defined by auser gesture, an embodiment also determines which of a plurality oflayout constraints to apply to the selected nodes based on the same usergesture as described above in reference to step 308 of flowchart 300.For example, in one embodiment, user gesture to constraint mappingmodule 204 is configured to select a vertical alignment constraint ifthe path defined by the user gesture corresponds to a vertical line andto select a horizontal alignment constraint if the path defined by theuser gesture corresponds to a horizontal line.

This is illustrated in part by FIG. 7, which shows a portion of thediagram depicted in FIGS. 5 and 6 after the diagram has been updated viaexecution of layout constraint application module 206 and rendered againto display device 104 via execution of diagram rendering module 208. Asshown in FIG. 7, path 602 of the user gesture has been interpreted as ahorizontal line and thus a horizontal alignment constraint has beenapplied to selected nodes 502, 504, 506, 510 and 512. In accordance withthis example, the horizontal alignment constraint has caused ahorizontal axis of each of the selected nodes to be aligned with ahorizontal guideline 702. Depending upon the implementation or theconfiguration of diagramming system 100, guideline 702 may or may not bemade visible to the user.

Various methods may be used to determine if the path associated with auser gesture is interpreted as a horizontal line or a vertical line. Forexample, in one embodiment, a bounding box is defined around the path ofthe user gesture, wherein the left and right sides of the bounding boxare placed at the left-most and right-most points of the path,respectively, and the top and bottom sides of the bounding box areplaced at the top-most and bottom-most points of the path, respectively.If the width of the bounding box exceeds the height of the bounding box,then the user gesture is determined to be a horizontal line. If theheight of the bounding box exceeds the width of the bounding box, thenthe user gesture is determined to be a vertical line. However, this isonly one technique and persons skilled in the relevant art(s) willreadily appreciate that numerous other techniques may be used todetermine if the path associated with a user gesture is to beinterpreted as a horizontal line or a vertical line.

In an embodiment in which elements of a diagram that are intersected bya path of a user gesture are selected for application of a layoutconstraint, the manner in which the path intersects one or more of theelements may be used to determine the type of layout constraint to beapplied. This will now be more fully explained with reference toflowchart 800 of FIG. 8. Although the method of flowchart 800 will bedescribed herein in reference to various elements of diagramming system100 as described above in reference to FIGS. 1 and 2, persons skilled inthe relevant art(s) will readily appreciate that the method is notlimited to that implementation and may be implemented by other systemsor elements.

As shown in FIG. 8, the method of flowchart 800 begins at step 802 inwhich user gesture to constraint mapping module 204 is executed toidentify a first element intersected by a path defined by a user gesturewherein the first element is a shape that comprises a plurality ofsides. For example, the first element may comprise a square, rectangleor other polygon. Since a user gesture may be captured over time, thepath defined by the user gesture may be analyzed in a temporal manner.Using such a temporal analysis, it may be determined which element of adiagram was first intersected by the path.

At step 804, user gesture to constraint mapping module 204 is executedto identify a side of the first element that was first intersected bythe path. As noted above, the path defined by the user gesture may beanalyzed in a temporal manner. Using such a temporal analysis, it may bedetermined which side of the first element was first intersected by thepath. This side may be thought of as the “point of entry” of the pathinto the first element.

At step 806, user gesture to constraint mapping module 204 is executedto identify a last element intersected by the path, wherein the lastelement also comprises a shape that comprises a plurality of sides. Thelast element intersected by the path may be determined by performing atemporal analysis of the path.

At step 808, user gesture to constraint mapping module 204 is executedto identify a side of the last element that was last intersected by thepath. A temporal analysis of the path may be used to determine whichside of the last element was last intersected by the path. This side maybe thought of as the “point of exit” of the path out of the lastelement.

At step 810, user gesture to constraint mapping module 204 is executedto select a layout constraint based on the sides of the first elementand the last element identified during steps 806 and 808. The layoutconstraint may comprise, for example, an alignment constraint. Thealignment constraint may comprise for example a horizontal, vertical ordiagonal alignment constraint although these examples are not intendedto be limiting.

Various examples of how the method of flowchart 800 may be used toselect a layout constraint will now be provided with respect to FIGS.9-14. For example, FIG. 9 depicts a portion of an exemplary diagram thathas been rendered to display device 104 via the execution of diagramrendering module 208. As shown in FIG. 9, the portion of the diagramincludes a plurality of elements 902, 904, 906 and 908, each of whichcomprises a top, bottom, left and right side. As also shown in FIG. 9, apath 910 associated with a user gesture has been mapped across andintersects each of the elements. From a temporal standpoint, path 910begins at the end that does not include an arrow and extends over timeto the end that does include an arrow. Thus, path 910 intersects element902 first and intersects element 908 last. Furthermore, path 910intersects the left side of element 902 first and intersects the bottomside of element 908 last.

In accordance with one embodiment, if the first side of the firstmulti-sided element intersected by a path defined by a user gesture isthe left side and the last side of the last multi-sided elementintersected by the path is the bottom side (as is the case in FIG. 9),then a diagonal alignment constraint will be applied to the firstmulti-sided element, the last multi-sided element and all interveningintersected elements. This is illustrated by FIG. 10, which shows theportion of the exemplary diagram from FIG. 9 after a diagonal alignmentconstraint has been applied to elements 902, 904, 906 and 908. Inaccordance with this example, the diagonal alignment constraint hascaused a diagonal axis of each of nodes 902, 904, 906 and 908 to bealigned with a diagonal guideline 1002. Depending upon theimplementation or the configuration of diagramming system 100, guideline1002 may or may not be made visible to the user.

FIGS. 11 and 12 provide an example of the use of the method of flowchart800 to select a horizontal alignment constraint. In particular, FIG. 11depicts a portion of an exemplary diagram that has been rendered todisplay device 104 via the execution of diagram rendering module 208. Asshown in FIG. 11, the portion of the diagram includes a plurality ofelements 1102, 1104, 1106, 1108, 1110 and 1112, each of which comprisesa top, bottom, left and right side. As also shown in FIG. 9, a path 1114associated with a user gesture has been mapped across and intersectseach of the elements. From a temporal standpoint, path 1114 begins atthe end that does not include an arrow and extends over time to the endthat does include an arrow. Thus, path 1114 intersects element 1102first and intersects element 1112 last. Furthermore, path 1114intersects the left side of element 1102 first and intersects the rightside of element 1112 last.

In accordance with one embodiment, if the first side of the firstmulti-sided element intersected by a path defined by a user gesture isthe left side and the last side of the last multi-sided elementintersected by the path is the right side (as is the case in FIG. 11),then a horizontal alignment constraint will be applied to the firstmulti-sided element, the last multi-sided element and all interveningintersected elements. This is illustrated by FIG. 12, which shows theportion of the exemplary diagram from FIG. 11 after a horizontalalignment constraint has been applied to elements 1102, 1104, 1106,1108, 1110 and 1112. In accordance with this example, the horizontalalignment constraint has caused a horizontal axis of each of nodes 1102,1104, 1106, 1108, 1110 and 1112 to be aligned with a horizontalguideline 1202. Depending upon the implementation or the configurationof diagramming system 100, guideline 1202 may or may not be made visibleto the user.

FIGS. 13 and 14 provide an example of the use of the method of flowchart800 to select a vertical alignment constraint. In particular, FIG. 13depicts a portion of an exemplary diagram that has been rendered todisplay device 104 via the execution of diagram rendering module 208. Asshown in FIG. 13, the portion of the diagram includes a plurality ofelements 1302, 1304, 1306 and 1308, each of which comprises a top,bottom, left and right side. As also shown in FIG. 13, a path 1310associated with a user gesture has been mapped across and intersectseach of the elements. From a temporal standpoint, path 1310 begins atthe end that does not include an arrow and extends over time to the endthat does include an arrow. Thus, path 1310 intersects element 1302first and intersects element 1308 last. Furthermore, path 1310intersects the top side of element 1302 first and intersects the bottomside of element 1308 last.

In accordance with one embodiment, if the first side of the firstmulti-sided element intersected by a path defined by a user gesture isthe top side and the last side of the last multi-sided elementintersected by the path is the bottom side (as is the case in FIG. 13),then a vertical alignment constraint will be applied to the firstmulti-sided element, the last multi-sided element and all interveningintersected elements. This is illustrated by FIG. 14, which shows theportion of the exemplary diagram from FIG. 13 after a vertical alignmentconstraint has been applied to elements 1302, 1304, 1306 and 1308. Inaccordance with this example, the vertical alignment constraint hascaused a vertical axis of each of nodes 1302, 1304, 1306 and 1308 to bealigned with a vertical guideline 1402. Depending upon theimplementation or the configuration of diagramming system 100, guideline1402 may or may not be made visible to the user.

The foregoing are merely some examples of how the method of flowchart800 may be used to select a layout constraint. Various other methodswill be apparent to persons skilled in the relevant art(s) based on theteachings provided herein.

FIGS. 15 and 16 illustrate a further embodiment in which the manner inwhich a path defined by a user gesture intersects elements of a diagrammay be used to determine the type of layout constraint to be applied tothe intersected elements. In accordance with such an embodiment, if thepath both begins and ends inside the same element, then a circularalignment constraint is applied to the intersected elements. By way ofexample, FIG. 15 depicts a portion of an exemplary diagram that has beenrendered to display device 104 via the execution of diagram renderingmodule 208. As shown in FIG. 15, the portion of the diagram includes aplurality of polygonal elements 1502, 1504, 1506, and 1508. As alsoshown in FIG. 15, a path 1510 associated with a user gesture has beenmapped across and intersects each of the elements. From a temporalstandpoint, path 1510 begins at the end that does not include an arrowand extends over time to the end that does include an arrow. Thus, path1510 both begins and ends inside element 1502. As a result, a circularalignment constraint will be applied to all of the intersected elements.This is illustrated by FIG. 16, which shows the portion of the exemplarydiagram from FIG. 15 after a circular alignment constraint has beenapplied to elements 1502, 1504, 1506 and 1508. In accordance with thisexample, the circular alignment constraint has caused each of elements1502, 1504, 1506 and 1508 to be aligned in accordance with a circularguideline 1602. Depending upon the implementation or the configurationof diagramming system 100, guideline 1602 may or may not be made visibleto the user.

In a further embodiment, the step of selecting one or more elements ofthe diagram based on the identified user gesture as described above inreference to step 306 of flowchart 300 comprises selecting elements ofthe diagram that are enclosed within a shape defined by the usergesture. This will now be illustrated with respect to FIGS. 17 and 18,each of which depicts a portion of an exemplary diagram that has beenrendered to display device 104 via the execution of diagram renderingmodule 208. As shown in FIG. 17, the portion of the diagram includes aplurality of elements 1702, 1704, 1706, 1708, 1710 and 1712. As furthershown in FIG. 17, a path 1714 associated with a user gesture has beenmapped onto the diagram. Path 1714 creates a shape that encloses orsurrounds each of elements 1706, 1708, 1710 and 1712. In accordance withone embodiment, diagram element selection module 202 is configured toselect nodes 1706, 1708, 1710 and 1712 as the elements to which a layoutconstraint will be applied by virtue of the fact that these elements areenclosed by the shape formed by path 1714.

In addition to performing node selection based on path 1714 defined by auser gesture, an embodiment also determines which of a plurality oflayout constraints to apply to the selected elements based on the sameuser gesture as described above in reference to step 308 of flowchart300. For example, in one embodiment, user gesture to constraint mappingmodule 204 is configured to select a grouping constraint if the pathdefined by the user gesture forms a shape that surrounds two or moreelements. In accordance with a grouping constraint, the elementsassociated with the constraint are kept together in a group and aboundary associated with such elements is prevented from overlappingwith other elements in a diagram.

This is illustrated by FIG. 18, which shows a portion of the diagramdepicted in FIG. 17 after the diagram has been updated via execution oflayout constraint application module 206 and rendered again to displaydevice 104 via execution of diagram rendering module 208. As shown inFIG. 18, a grouping constraint has been applied to selected elements1706, 1708, 1710 and 1712 such that those elements are kept togetherwithin a particular area, the boundary of which is denoted by boundaryguideline 1802. This boundary may be prevented from overlapping withother elements in the diagram. Depending upon the implementation or theconfiguration of diagramming system 100, boundary guideline 1802 may ormay not be made visible to the user.

In certain embodiments described above, the application of an alignmentconstraint to selected elements in a diagram results in the selectedelements being center aligned with respect to a constraint guideline.However, in alternate embodiments, elements in a diagram can be alignedusing other offsets. For example, in an embodiment in which elements ofa diagram include ports and in which relationships between elements aredenoted by edges that connect ports, the elements can be aligned bytheir ports so that the edges connecting the elements are exactlyhorizontal, vertical, diagonal, etc.

An example of this will now be illustrated with respect to FIGS. 19 and20, each of which depicts a portion of an exemplary diagram that hasbeen rendered to display device 104 via the execution of diagramrendering module 208. As shown in FIG. 19, the portion of the diagramincludes a plurality of nodes 1902, 1904, 1906 and 1908 and a pluralityof edges 1912, 1914 and 1916. Edge 1912 connects a port 1922 of node1902 to a port 1926 of node 1904, edge 1914 connects a port 1924 of node1904 to a port 1928 of node 1906, and edge 1916 connects a port 1930 ofnode 1906 to a port 1932 of node 1908. As also shown in FIG. 19, a path1940 associated with a user gesture has been mapped across andintersects each of the elements. As a result, a horizontal alignmentconstraint will be applied to all of the intersected elements. FIG. 20shows the portion of the exemplary diagram from FIG. 19 after ahorizontal alignment constraint has been applied to elements 1902, 1904,1906 and 1908. In accordance with this example, the horizontal alignmentconstraint has caused the ports of elements 1902, 1904, 1906 and 1908 tobe aligned in such a manner that the edges connecting the elements areexactly horizontal.

Although the foregoing describes the use of user gestures to selectelements of a diagram and to apply layout constraints to the selectedelements, the concepts described above can also be applied in a similarmanner to modify or merge existing layout constraints associated withelements in a diagram. For example, a user gesture that selects certaindiagram elements may also be interpreted as a request to modify anexisting layout constraint that involves those elements. As anotherexample, a user gesture that selects a first set of diagram elements anda second set of diagram elements can also be interpreted as a request toassociate a layout constraint that involves the first set of diagramelements with the second set of diagram elements. This latter scenariowill now be further described with reference to flowchart 2100 of FIG.21.

As shown in FIG. 21, the method of flowchart 2100 begins at step 2102 inwhich rendering module 208 is executed by processing unit 112 to renderat least a portion of a diagram to display device 104. The diagramcomprises a plurality of elements.

At step 2104, user gesture processing module 124 is executed byprocessing unit 112 to identify a user gesture based on input receivedvia at least one of user input device(s) 106.

At step 2106, diagram element selection module 202 is executed byprocessing unit 112 to select one or more first elements of the diagramand one or more second elements of the diagram based on the user gestureidentified during step 304.

At step 2108, diagramming module 122 is executed by processing unit 112to identify a layout constraint associated with the first selectedelement(s).

At step 2110, layout constraint application module 206 is executed byprocessing unit 112 to apply the layout constraint identified duringstep 2108 to the second selected element(s).

At step 2112, diagram rendering module 208 is executed by processingunit 112 to render at least a portion of the diagram to display device104 after application of the layout constraint identified during step2108 to the second selected element(s). During this step, if theapplication of the identified layout constraint to the second selectedelement(s) has caused a change in the layout of the diagram, that changemay be made apparent to the user when the diagram, or portion thereof,is viewed by the user on display device 104.

Additional embodiments are also contemplated herein. For example, amethod implemented in a processor-based computing system is provided.The method includes rendering at least a portion of a diagram to adisplay device coupled to the computing system, the diagram comprising aplurality of elements, and identifying a user gesture based on inputreceived via at least one user input device coupled to the computingsystem. The method also includes selecting one or more elements of thediagram based on the identified user gesture, and selecting a layoutconstraint from among a plurality of layout constraints based on theidentified user gesture, wherein each layout constraint controls amanner in which elements of a diagram are arranged when rendered to adisplay device. The method further includes applying the selected layoutconstraint to the selected element(s), and rendering at least a portionof the diagram to the display device after application of the selectedlayout constraint to the selected element(s).

In the method, identifying the user gesture may comprise determining ifthe input corresponds to a user gesture in a library of predefined usergestures. In the method, identifying the user gesture based on inputreceived via the at least one user input device may comprise identifyingthe user gesture based on input received via at least one of a mouse, atouch screen, or a video capture device.

In the method, selecting the one or more elements of the diagram basedon the identified user gesture may comprise selecting elements of thediagram that are intersected by a path defined by the user gesture. Inthe method, selecting the layout constraint based on the identified usergesture may comprise selecting a vertical alignment constraint if thepath defined by the user gesture corresponds to a vertical line. In themethod, selecting the layout constraint based on the identified usergesture may comprise selecting a horizontal alignment constraint if thepath defined by the user gesture corresponds to a horizontal line. Inthe method, selecting the layout constraint based on the identified usergesture may comprise selecting a circular alignment constraint if thepath defined by the user gesture begins and ends inside the sameelement. In the method, selecting the layout constraint based on theidentified user gesture may comprise identifying a first elementintersected by the path, the first element comprising a plurality ofsides, identifying a side of the first element that was firstintersected by the path, identifying a last element intersected by thepath, the last element comprising a plurality of sides, identifying aside of the last element that was last intersected by the path, and/orselecting an alignment constraint based on the identified sides of thefirst element and the last element.

In the method, selecting the one or more elements of the diagram basedon the identified user gesture may comprise selecting elements of thediagram that are enclosed within a shape defined by the user gesture,and selecting the layout constraint based on the identified user gesturemay comprise selecting a grouping constraint.

In the method, identifying the user gesture based on input received viaat least one user input device coupled to the computing system maycomprise identifying a multi-touch user gesture.

The method may further include rendering a line that follows a pathdefined by the user gesture to the display device.

A computer-readable medium having computer-executable instructions forcausing a computer to perform the steps recited in the method is alsoprovided.

A system is also provided. The system may include a display device, atleast one user input device, a memory that stores at least a diagrammingmodule and a user gesture processing module, and a processing unit thatexecutes the diagramming module to render at least a portion of adiagram to the display device, the diagram comprising a plurality ofelements.

The processing unit may further execute the user gesture processingmodule to identify a user gesture based on input received via the atleast one user input device, and the processing unit may further executethe diagramming module to select one or more elements of the diagrambased on the identified user gesture, to select a layout constraint fromamong a plurality of layout constraints based on the identified usergesture, wherein each layout constraint controls a manner in whichelements of a diagram are arranged when rendered to a display device, toapply the selected layout constraint to the selected element(s) and torender at least a portion of the diagram to the display device afterapplication of the selected layout constraint to the selectedelement(s).

In the system, the memory may further store a library of predefined usergestures and the processing unit may execute the user gesture processingmodule to determine if the input corresponds to a user gesture in thelibrary of predefined user gestures.

In the system, the at least one user input device may comprise at leastone of a mouse, a touch screen, or a video capture device. In thesystem, the processing unit may execute the diagramming module to selectelements of the diagram that are intersected by a path defined by theuser gesture. In the system, the processing unit executes thediagramming module to select elements of the diagram that are enclosedwithin a shape defined by the user gesture. In the system, theprocessing unit may execute the diagramming module to render a line thatfollows a path defined by the user gesture to the display device.

A method implemented in a processor-based computing system is alsoprovided. The method includes rendering at least a portion of a diagramto a display device coupled to the computing system, the diagramcomprising a plurality of elements, and identifying a user gesture basedon input received via at least one user input device coupled to thecomputing system. The method also includes selecting one or more firstelements of the diagram and one or more second elements of the diagrambased on the identified user gesture, and identifying a layoutconstraint associated with the first selected element(s), wherein theidentified layout constraint controls a manner in which the firstselected element(s) are arranged when rendered to the display device.The method further includes applying the identified layout constraint tothe second selected elements(s), and rendering at least a portion of thediagram to the display device after application of the identified layoutconstraint to the second selected element(s).

A computer-readable medium having computer-executable instructions forcausing a computer to perform the steps recited in the method is alsoprovided.

III. Example Computer System Implementation

FIG. 22 depicts an example computer 2200 that may be used to implementdiagramming system 100 as described above in reference to FIG. 1.Computer 2200 may represent a general-purpose computing device in theform of a conventional personal computer, a mobile computer, or aworkstation, for example, or computer 2200 may be a special purposecomputing device. The description of computer 2200 provided herein isprovided for purposes of illustration, and is not intended to belimiting. Embodiments may be implemented in further types of computersystems, as would be known to persons skilled in the relevant art(s).

As shown in FIG. 22, computer 2200 includes a processing unit 2202, asystem memory 2204, and a bus 2206 that couples various systemcomponents including system memory 2204 to processing unit 2202.Processing unit 2202 may comprise one or more processors or processingcores. Bus 2206 represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. System memory 2204 includes readonly memory (ROM) 2208 and random access memory (RAM) 2210. A basicinput/output system 2212 (BIOS) is stored in ROM 2208.

Computer 2200 also has one or more of the following drives: a hard diskdrive 2214 for reading from and writing to a hard disk, a magnetic diskdrive 2216 for reading from or writing to a removable magnetic disk2218, and an optical disk drive 2220 for reading from or writing to aremovable optical disk 2222 such as a CD ROM, DVD ROM, or other opticalmedia. Hard disk drive 2214, magnetic disk drive 2216, and optical diskdrive 2220 are connected to bus 2206 by a hard disk drive interface2224, a magnetic disk drive interface 2226, and an optical driveinterface 2228, respectively. The drives and their associatedcomputer-readable media provide nonvolatile storage of computer-readableinstructions, data structures, program modules and other data for thecomputer. Although a hard disk, a removable magnetic disk and aremovable optical disk are described, other types of computer-readablemedia can be used to store data, such as flash memory cards, digitalvideo disks, random access memories (RAMs), read only memories (ROM),and the like.

A number of program modules may be stored on the hard disk, magneticdisk, optical disk, ROM, or RAM. These programs include an operatingsystem 2230, one or more application programs 2232, other programmodules 2234, and program data 2236. Application programs 2232 orprogram modules 2234 may include, for example, any of the softwaremodules described herein, such as any of the software modules describedin reference to FIGS. 1 and 2, as well as logic for performing any ofthe various method steps described herein, such as logic for performingany of the method steps of flowcharts 300, 400, 800 or 2100.

A user may enter commands and information into the computer 2200 throughinput devices such as keyboard 2238 and pointing device 2240. Otherinput devices (not shown) may include a microphone, joystick, gamecontroller, scanner, or the like. These and other input devices areoften connected to the processing unit 2202 through a serial portinterface 2242 that is coupled to bus 2206, but may be connected byother interfaces, such as a parallel port, game port, or a universalserial bus (USB).

A monitor 2244 or other type of display device is also connected to bus2206 via an interface, such as a video adapter 2246. In addition to themonitor, computer 2200 may include other peripheral output devices (notshown) such as speakers and printers.

Computer 2200 is connected to a network 2248 (e.g., a local area networkor wide area network such as the Internet) through a network interfaceor adapter 2250, a modem 2252, or other means for establishingcommunications over the network. Modem 2252, which may be internal orexternal, is connected to bus 2206 via serial port interface 2242.

As used herein, the terms “computer program medium” and“computer-readable medium” are used to generally refer to media such asthe hard disk associated with hard disk drive 2214, removable magneticdisk 2218, removable optical disk 2222, as well as other media such asflash memory cards, digital video disks, random access memories (RAMs),read only memories (ROM), and the like.

As noted above, computer programs and modules (including applicationprograms 2232 and other program modules 2234) may be stored on the harddisk, magnetic disk, optical disk, ROM, or RAM. Such computer programsmay also be received via network interface 2250 or serial port interface2242. Such computer programs, when executed or loaded by an application,enable computer 2200 to implement features of embodiments discussedherein. Accordingly, such computer programs represent controllers of thecomputer 2200.

Embodiments are also directed to computer program products comprisingsoftware stored on any computer useable medium. Such software, whenexecuted in one or more data processing devices, causes a dataprocessing device(s) to operate as described herein. Embodiments mayemploy any computer-useable or computer-readable medium, known now or inthe future. Examples of computer-readable mediums include, but are notlimited to storage devices such as RAM, hard drives, floppy disks, CDROMs, DVD ROMs, zip disks, tapes, magnetic storage devices, opticalstorage devices, MEMS-based storage devices, nanotechnology-basedstorage devices, and the like.

IV. Conclusion

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and details can be made thereinwithout departing from the spirit and scope of the invention. Thus, thebreadth and scope of the present invention should not be limited by anyof the above-described exemplary embodiments, but should be defined onlyin accordance with the following claims and their equivalents.

What is claimed is:
 1. A method implemented in a processor-basedcomputing system, comprising: rendering at least a portion of a diagramto a display device of the processor-based computing system, the diagramcomprising a plurality of different elements; identifying a first usergesture and subsequently selecting a first subset of elements from amongthe plurality of different elements of the diagram based on theidentified first user gesture; selecting, automatically, a layoutconstraint from among a plurality of layout constraints based on a pathor a shape of the identified first user gesture, the selected layoutconstraint controlling a manner in which elements of the diagram arearranged; applying the selected layout constraint to the selected firstsubset of elements to generate a first layout of the diagram;identifying a second user gesture and subsequently selecting the firstsubset of elements, and a second subset of elements from among theplurality of different elements of the diagram, based on the identifiedsecond user gesture; and applying the selected layout constraint to theselected second subset of elements based on the identified second usergesture to generate a second layout of the diagram.
 2. The method ofclaim 1, further comprising at least one of: rendering at least aportion of the diagram in the first layout to the display device; orrendering at least a portion of the diagram in the second layout to thedisplay device.
 3. The method of claim 1, wherein identifying the firstuser gesture or identifying the second user gesture comprises:determining if the first user gesture or the second user gesturerespectively corresponds to a user gesture in a library of predefineduser gestures.
 4. The method of claim 1, wherein at least one of thefirst user gesture or the second user gesture comprises motions of auser in a space.
 5. The method of claim 4, wherein identifying the firstuser gesture or identifying the second user gesture comprisesidentifying the first user gesture or identifying the second usergesture respectively based on input received via at least one of a videocapture device or one or more motion tracking sensors.
 6. The method ofclaim 1, wherein applying the selected layout constraint to the selectedsecond subset of elements comprises merging the second subset ofelements with the selected first subset of elements according to theidentified layout constraint.
 7. The method of claim 1, whereinselecting the first subset of elements comprises selecting elements ofthe diagram that are enclosed within a shape defined by the usergesture.
 8. The method of claim 7, wherein selecting the layoutconstraint comprises selecting one of a horizontal alignment constraint,a vertical alignment constraint, a diagonal alignment constraint, acircular alignment constraint, or a grouping constraint.
 9. Acomputer-readable storage device storing computer-executableinstructions that, when executed by a processor-based computing system,cause the processor-based computing system to perform a method, themethod comprising: rendering at least a portion of a diagram to adisplay device coupled to the computing system, the diagram comprising aplurality of elements; identifying a user gesture based on inputreceived via at least one user input device coupled to the computingsystem, the user gesture comprising one of a touch gesture or a trackedspatial motion of a user; selecting, subsequent to said identifying, oneor more first elements of the diagram and one or more second elements ofthe diagram based on the identified user gesture; identifying a layoutconstraint associated with the selected first element(s) from among aplurality of layout constraints, the identified layout constraintcontrolling a manner in which the selected first element(s) are arrangedwhen rendered to the display device; applying the identified layoutconstraint to the selected second elements(s) based on the identifieduser gesture; and rendering at least a portion of the diagram to thedisplay device after application of the identified layout constraint tothe selected second element(s).
 10. The computer-readable storage deviceof claim 9, wherein the identified layout constraint is based on a pathor a shape of a prior user gesture associated with the selected firstelement(s).
 11. The computer-readable storage device of claim 9, whereinidentifying the user gesture based on input received via the at leastone user input device comprises identifying the user gesture based oninput received via at least one of a video capture device or one or moremotion tracking sensors.
 12. The computer-readable storage device ofclaim 9, wherein applying the identified layout constraint to the secondselected elements(s) comprises merging the second selected elements(s)with the first selected elements(s) according to the identified layoutconstraint.
 13. The computer-readable storage device of claim 9, whereinapplying the identified layout constraint to the selected secondelements(s) is performed on the selected second elements(s) separatelyfrom the selected first element(s).
 14. The computer-readable storagedevice of claim 9, wherein the identified layout constraint comprisesone of a horizontal alignment constraint, a vertical alignmentconstraint, a diagonal alignment constraint, a circular alignmentconstraint, or a grouping alignment constraint.
 15. A method implementedin a processor-based computing system, comprising: rendering at least aportion of a diagram to a display device coupled to the computingsystem, the diagram comprising a plurality of elements; identifying auser gesture based on input received via at least one user input devicecoupled to the computing system, the user gesture comprising one of atouch gesture or a tracked spatial motion of a user; selecting,subsequent to said identifying, one or more first elements of thediagram and one or more second elements of the diagram based on theidentified user gesture; identifying a layout constraint associated withthe selected first element(s) from among a plurality of layoutconstraints, the identified layout constraint controlling a manner inwhich the selected first element(s) are arranged when rendered to thedisplay device; applying the identified layout constraint to theselected second elements(s) based on the identified user gesture; andrendering at least a portion of the diagram to the display device afterapplication of the identified layout constraint to the selected secondelement(s).
 16. The method of claim 15, wherein the identified layoutconstraint is based on a path or a shape of a prior user gestureassociated with the selected first element(s).
 17. The method of claim15, wherein identifying the user gesture based on input received via theat least one user input device comprises identifying the user gesturebased on input received via at least one of a video capture device orone or more motion tracking sensors.
 18. The method of claim 15, whereinapplying the identified layout constraint to the selected secondelements(s) comprises merging the selected second elements(s) with theselected first elements(s) according to the identified layoutconstraint.
 19. The method of claim 15, wherein applying the identifiedlayout constraint to the selected second elements(s) is performed on theselected second elements(s) separately from the selected firstelement(s).
 20. The method of claim 15, wherein the identified layoutconstraint comprises one of a horizontal alignment constraint, avertical layout constraint, a diagonal alignment constraint, a circularalignment constraint, or a grouping alignment constraint.